1. Field of the Invention
The present invention relates to a robotics handling system for storing and handling articles. More particularly, the present invention relates to a laser targeting system for use with a robotics system for handling videocassettes in an automated programmable sequence.
2. Description of the Prior Art
Existing prior art videocassette storage, handling and sequencing systems typically embody one of two forms. In certain systems, videotape cassettes are stored on a movable carousel and the desired cassette is positioned for removal by rotation of the carousel. The cassette is then loaded into the tape transport by a robotics handling mechanism. Other robotics sequencing systems incorporate one or more stationary columns of storage bins in which cassettes are held and an elevator robotics system loads the designated cassettes into specific transport units. In these latter systems, it is known to place a bar code label on the videocassette and use a bar code reader to allow a computer control system to determine the location of the cassette to be retrieved and control the movement of the cassette from a storage bin to a tape transport. Exemplary of such systems are U.S. Pat. No. 4,654,727 (which discloses an automatic cassette handling and sequencing system utilizing a bar code reader and is capable of storing hundreds of cassettes for handling) and U.S. Pat. No. 4,846,619 (which discloses a robotics handling system having a plurality of columns of storage bins located about a circle),
While recently developed systems such as the ones embodied in the above-identified U.S. patents have expedited the handling and sequencing of cassettes in robotics systems, the adjustment of cassette loading and handling pickup points has often been a difficult and time consuming effort. Fine tuning and adjusting of pickup points (or "targeting") is necessary to ensure that the robotics can properly grasp a cassette and insert it into a transport. Targeting is generally necessary at the time of installation of a robotics system in order to adjust the handling robotics to compensate for inconsistencies in manufacturing (or for manufacturing tolerances) and for the effects of stress being applied to various parts during installation. After installation and the initial targeting, the system may become slightly misaligned during use. For example, misalignment may occur when a video transport in the system is serviced or the entire system moved, or due to normal wear and tear such as belt stretch and fatigue. The effect of such misalignment serves to handicap the sequencing and handling capabilities of the system. In existing systems, however, both initial targeting and subsequent retargeting require significant time and effort and manual adjustment of the entire system.